Nico Rosberg was fastest in opening practice ahead of the inaugural Formula 1 Russian Grand Prix.
Marking the debut of the Sochi Autodrom, Rosberg posted a best lap of 1:42.311 to head his Mercedes team-mate and title rival Lewis Hamilton to the top spot by 0.065 seconds.
Jenson Button, who topped the time sheets early on, was third, two tenths clear of Ferrari’s Fernando Alonso, and half a second clear of his McLaren team-mate Kevin Magnussen in fifth.
Force India’s Sergio Perez ended the session sixth fastest, ahead of local favourite Daniil Kvyat in seventh for Toro Rosso, while Kimi Raikkonen was eight in the second Ferrari.
Jean-Eric Vergne and Valtteri Bottas rounded out the top ten for Toro Rosso and Williams respectively, the Finn ahead of his team-mate Felipe Massa in 11th despite missing the final 30 minutes of the session after a bizarre tyre blanket failure.
Daniel Ricciardo was just 12th for Red Bull, in what was a low-key morning session for the Milton Keynes-based squad, with Sebastian Vettel mired down in 14th, the pair split in 13th by Nico Hulkenberg.
Sauber stand-in Sergey Sirotkin, driving in front of his home crowd in opening practice, was 17th fastest on his first run in a Formula 1 session, four tenths shy of his experienced team-mate Adrian Sutil in 15th.
The two Lotus drivers were 16th and 18th, Pastor Maldonado and Romain Grosjean split by just three tenths of a second.
Roberto Merhi, sanding in for Kamui Kobayashi in opening practice, survived a spin late on to finish 19th for Caterham, two tenths clear of regular driver Marcus Ericsson.
Max Chilton was 21st in the sole Marussia, after the team opted to run just a single car as a mark of respect to the injured Jules Bianchi.
Image courtesy of Daimler